Recovery of proteids from waste liquors of the hide-treating art.



RECOVERY OF- PROTEIDS FROM WASTE-LIQUORS 0F THE HIDE TREATING ART. y

APPLICATION FILED MAR.'2, i918.

ATTORNEYS.

v UNITED STATES PATENT oEEroE.

YORK, N. Y., A CORPORATION 0F DELAWARE. -p i RECOVERY oF raoTEIDs Enom WASTE EreUoEs or 'THE HIDE-TREA'TING ART.

Specification of Letters Patent.

Patented Aug.` 6, 1*'918.

Application led March 2, 1918. Serial No. 219,981.

To all whom t may concern:

Be it known that I, CHARLES LEE PEGI, a citizen of the United States, residin at New York city, inthe county of New ork, State of New York, have invented certain new and useful Improvements in Recovery of Proteids froml Waste Liquors of the Hide- Treating -Art; and I do hereby declare the following to be a full, clear, and exact 'description of the invention, such as will enable others skilled in the art to which it appertains tomake and use the same. y The present invention relates to the recovery, in a form available for use in the fertilizer industry, in the manufacture of amteid. substances from the lime process, which are mainly in solution in the waste liquors from that process, but which are, 4in part, in suspension therein, are recovered, in their substantial entirety, in a condition which renders them non-putrefiable, and which ultimately permits their nitrogen content to be made available, as stated, for use as fertilizer, or in the production of ammonia, or for any other useful purpose. The invention has the further advantage that the efiiuent or final waste liquor left after the precipitation of the recovered proteids contains no hydrated alkali, and no free acid (except a certain quantity of CO2 held in solution therein), so that said final efiiuent is not a meance to public health, orto fish life and can be discharged, without disadvantage,

lntorunning streams. It is a further merit of the invention that in the application of the ultimate fertilizer to the soil, it is devoid of all noxious bacteria which, iny any way, could have been present in the original hides from which the waste liquors were derived,

so that the application of the fertilizer to the soil is wholly beneficent.

In the treatment of hides, preparatory to the tanning thereof, the raw hides are first subjected to a cleansing' process, having for its object to swell them somewhat and to deprive them, for the most part, of adhering foreign substances, the cleansing being due to the Washing and solvent power of water, assisted to a greater or less extent, by agitation, beating, rubbing, or the like. The hides, which, in the usual practice, have been salted, are then subjected tothe so-called lime process, well known in the art, wherein they are subjected to the action of caustic lime, sodiumsulfid, sodium hydrate, and the like for the removal of greasy particles, fieshings and hair. l

` CHARLES LEE PECK, 0F NEW YORK, N. Y., ASSIGNOR T0 THEDORRCOMPANY, OF NEW In accordance with the present invention,

the waste liquor from this lime process isv received in a receiving tank or cistern, wherein there is effected a separation of the undissolved lime salts, sand, and silt, in any` suitable way, as, for instance, by sedimentation. The supernatant wastek liquor or efiluent from this tank or cistern has in solution (and partly in suspension) the proteids Which it is the main purpose of the invention to recover. For this purpose, the said supernatant liquor or eiiiuent is conveyed into another tank or cistern, wherein the recovery of the proteids is effected.

The agent employed for the recovery of the proteids is the acid waste liquors from the tanning processes such as vegetable tanning, chrome tanning, and the like. In order to remove, for the most part at least, inert sediments, etc., and for the further purpose of storing the waste tan liquors for convenience in the use of the process, the liquors are received in a suitable tank or cistern, wherein the resins, tan sediments, and other like inert materials are permitted to settle out, by sedimentation, or to be otherwise separated. The efiluent from this sedimentation tank or cistern is then available for use in the recovery of the proteids in solution or in suspension, hereinbefore the two-fold function of permitting the separation of the gums, tan sediments and like inert substances, and which also serve as a storage receptacle wherein the tan liquors may be collected, prior to their passage into the tank or cistern wherein they are to react with the proteids in solution or in suspension in the lime process effluent.

The final steps in Athe process characterizY ing the present invention, will now be readily understood. The eluent from the storage and sedimentation tank or cistern containing the waste tan liquors 1s discharged into the tank or cistern containing the eiiiuent from the sedimentation tank of the lime process waste liquors. The discharge of the eluent from the two sedimentation tanks or cisterns into thereaction tank or cistern may be simultaneous, or, if preferred, may be successive. ln either event, the proteids react with the waste tan liquor and are'precipitated, in their substantial entirety in the bottom of the reaction tank or cistern. The precipitate constitutes the nitrogenous material characteristic of the invention, and the eiiluent from the reaction tank or cistern may be permitted to go to waste, or may be subsequently treated for the recovery of any of the values contained therein. Particularly, however, it is to be noted that this effluent contains no hydrated alkali and no free acid so that it can be discharged into the running streams without polluting the stream and without other disadvantages.

The precipitated proteids may then be removed from the reaction tank or cistern and are practically insoluble in water and are non-putrescible. They are capable of being converted into available fertilizer material for plant assimilation, by treatment with sulfuric acid, and may be dried, without loss, at temperatures so high as to entirely destroy any bacterial life therein. ln fact, the precipitated proteids may be regarded as tanned by their reaction with the tan liquors, which have not only precipitated the proteids held in solution, but which have exerted' upon them and upon the proteid particles held in suspension, the preservative effects due to the action of tanning liquors upon proteid substances under such conditions as prevail in the reaction tank or cistern.

1n the accompanying drawing is shown a dow sheet indicating generally the steps ofivavce the process. In this drawing, A indicates the sedimentation tank or cistern wherein the undissolved lime salts, sand, silt, etc., are separated from the supernatant eiiluent. B indicates the tankor cistern for the storage and sedimentation of the waste liquors from the tanning process; and C indicates the reaction tank or cistern wherein the combined effluents from the tanks or cisterne A and B are received and wherein the proteids held in solution and in suspension are recovered as products available for use in the manufacture of fertilizers, ammonia, or for any other useful purpose.

Having thus described my invention, what I claim is:

l. The method of recovering, fromthe waste liquors of the lime process of the hidetreating art, material availablel for use in the manufacture of fertilizers and other useful products which consists in 'separating from said liquors an eiiiuent containing proteids and precipitating and preserving against putrescence said proteids by subjecting them to the action of the waste liquors from the tanning process; substantially as described.

2. The method of recovering, from waste liquors of the lime process ofthe hide-treating art, material available for use in the manufacture of fertilizers and other useful products which consists in separating from said liquors an eiiuent containing proteids partly in solution and partly in suspension, and precipitating and preserving against putrescence said proteids by subjecting them to the action of the waste liquors from the tanning process; substantially as described.

3. The method of recovering, from waste liquors of the lime process-of the hidetreat ing art, materiai available for use in the manufacture of fertilizers and-other useful products, which consists in separating out from said liquors suspended lime salts, sand and the like, passing the residual effluent into a reaction receptacle and subjecting it therein to reaction with the solvent portion of the waste liquors of the tanning process, and recovering the resulting precipitate in a substantially water-insoluble and non-putrescent condition; substantially as described.

In testimony whereof I aiiix my signature.

CHARLES LEE PECK. 

